Ferritic stainless steels include grade like 430 and contain only chromium as a major alloying element. The quantity of chromium present ranges from 10.5% to 18%.

They are known for their moderate corrosion resistance and poor fabrication properties. Fabrication properties can be improved by alloy modifications and are satisfactory in grades such as 434 and 444. Ferritic stainless steels cannot be hardened by heat treatment and are always used in the annealed condition. Ferritic stainless steel are magnetic. They are also not susceptible to stress corrosion cracking. Weldability is acceptable in thin sections but decreases as section thicknesses increase.

Martensitic Stainless Steels

High carbon and lower chromium content are the distinguishing features of martensitic stainless steels when compared with ferritic stainless. Martensitic stainless steel include 410 and 416. Hardened martensitic steels cannot be successfully cold formed. They are magnetic, have moderate corrosion resistance and poor weldability. Martensitic stainless steel is a specific type of stainless steel alloy.